Drill.



PATENTED 13mm' No. 874,894I

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- PATENTBD DBG. 24,' 1907. G.E.LYNGH.

DRILL. APPLICATION FILED APR. 6. 1905.

2 SHEETS-SHEET 2.

Illll! Witnao'ow IINITED STATES. PATENT OFFICE.

GEORGE E. LYNCH, OF COLUMBUS, OHIO, ASSIGNOR TO JOSEPH A. JEFFREY, OF COLUMBUS,

- OHIO.

Specification of Letters Patent.

Patented Dec. 24, 1907.

Application filed April 6, 1905. Serial No. 254,169.

T0 all whom t may concern:

Be it known that I, GEORGE E. LYNCH, a citizen of the`United States, residing at Columbus, in the county of Franklin and State of Ohio, have invented certain new and usefnl Improvements in Drills, of which the following is a specification, reference being had therein to the accompanying drawing.

This invention relates to an improvement in rock drills.

It pertains particularly to that class of reciprocating drills in which a spring is alternately compressed and then released in order to drive the drill bit forward to deliver its blow.

Figure 1 is a plan view of a drill embodying my improvements, the bearings for the crank-shaft being represented in section, and the cover of the casing being removed. Fig. 2 is a central vertical longitudinalsection of the same. Fig. 3 is a central longitudinal horizontal section of a portion of the drill. Fig. 4 is a section on the line 4-4. of Fig. 3. Fig. 5 is a section of the rear cylindrical part 1d of the casing. Fig. 6 is a perspective view of one of the toggle levers.

In the drawing 1 indicates, as an entirety, the shell or casing of the drill. It com rises a forward cylindrical part 1a, a centra relatively expanded part 1b having the detachable cover 1e and the rear cylindrical part 1d. The cover 1C is pivotally connected at 2 to the front section of the frame and has its rear end suitably bolted to adjacent parts of the casing as indicated at 3.

4 indicates the driving shaft mounted transversely at the rear end of the frame or casing in a bearing 5 carried thereby. Power may be applied for rotating this shaft in any well known manner and by any well known means.

6 is a gear wheel rigidly secured tothe shaft at one side ofthe casing.

7 is a crank shaft transversely mounted in the casing in the bearings 8-8 at eitherside thereof and above the cylindrical part 1d, and having its crank pin 7 located centrally within said casing. 9 is a pinion rigidly secore'd tu the said crank shaft and meshing with the driving gear 6.

10-10 are fly wheels rigidly secured to the crank shaft at either end thereof.

11 indicates as an entirety the reciprocating piston rod or hammer rod which is adapted to deliver the blow to the drilling tool or bit. This rod is arranged centrally within the casing lnand extends from the rear end thereof through the front end thereof and at its forward end carries a tool holding device indicated by 12. The portion 11 of the said piston rod within the cylinder 18L is of relatively larger diameter than the rest of the rod, and at each end of this enlarged section there is a shoulder or collar, the front one being indicated by 11a and the rear one by 11b. The collarllb is fitted to reciprocate in the bearing 1e at the rear of the cylinder 1a and serves in connection with the cross-head 16, to be described, to guide and direct the movements of the rod 11.

13 is a powerful spring surrounding the part 11 of the piston rod within the cylinder 1a and bearing at its front end against the collar 11a and at its rear end against the rear wall of the said cylinder.

14 is a head or cap fitted to the front end of the cylinder 1a and having the centrally` arranged passageway 14 through which the front end of the piston rod extends. 14a indicates a recess in the said head and 15 a buffer spring bearing at its rear end against the front face of the collarl 11a and at its front end against the vertical wall of the recess 14a. Any other well known-style of buffer may be interposed between the said collar and head 14.

At its rear end the piston or hammer rod lleXtends through the crosshead 16, preferably cylindrical in form and fitted to reciprocate within -the cylinder or guide 1d. Immediately in the rear of this crosshead the piston rod 11 is screw threaded as indicated at 11.

17 is a nut fitted to the screw threaded portion 11C of the piston rod and abutting at its front end against the rear end of the cross head 16.

11d isa transverse slot through the piston rod and 17 is a lock pin passed transversely through said nut and through said slot and adapted to hold the nut against turning relatively to the piston rod when it has been adjusted thereon. It will be noted that the slot itself is relatively wide on longitudinal lines of the piston rod so as to permit the said adjustment of the nut forward and back thereon and of its being locked by the pin 17 in its various positions of adjustment.

18, 18', 1.9 and 19 indicate toggle links or joints arranged at either side of the piston rodll in vertical longitudinal planes within the part 1b of the casing the links of the first pair are pivotally connected together at 18a and those of the second pair'at 19a.

16 16 indicate recesses in the cross head 16 at either side of the piston rod 11 and adapted to receive the rear ends of the links 1S and 19 and to permit their' oscillation about the pivots by means of which they are respectivelyT connected to the said crosshead. The walls of the cylinder or guide ld are als-o' recessed at either side as indicated at 1" lf to accommodate links 1S and 19 and allow for their oscillation about the said axes.

At their front ends the links 18 and 19 have laterally projecting bosses or journals 18h, 19b respectively. 20, 20 are levers adapted to actuate the toggle joints or links. At their lower ends these levers carry cylin drical laterallyT extending bosses or journals 20 into which the bosses or journals 18h, 19b of the toggle joints 18 and 19 respectively are fitted to rotate. Each of the toggle levers 20 is recessed on its inner face as indicated at 29at to receive the lower front end of the toggle joints 1S and 19. The faces or walls 20b and 2OC of the recesses 20tL in these toggle levers are arranged at an acute angle to each other and each is adapted to engage with the adjacent edge of the toggle jointto be actuated by it during the operation of the mechanism to be hereinafter described.

The bosses or journals 20 of the toggle joint actuating levers are mounted in bearings 1g, 1g in the Walls of the frame or casing. 21, 21 are bolts fitted into the bosses or journals 1Sb and 19b of the front toggle links or joints and 22, 22 are washers arranged between the heads of said bolts and the casing; these bolts and washers being adapted to hold the toggle joints and their actuating levers in proper relation within the frame or casing.

23 is a connecting rod pivotally connected at its front end to a crank pin 7 and at its rear end to the pin 24 which is mounted in the upper ends of the toggle actuating levers 2o, 2o.

The tool or bit is rotated during its reciprocating movements in the following manner. 25 is a spiral pinion rigidly secured to the power shaft 4 in the central longitudinal planes of the device and preferably above the piston or hammer rod and at the rear end thereof, 26 is a gear meshing with the said spiral pinion and having its axis of rotation coincident with the axis of the piston or hammer rod which extends through it and is adapted to reciprocate within the said gear. Preferably the piston or hammer rod is reduced in diameter at this point as indicated at 11C and carries feathers or splines 11f which are fitted into keyways within the said gear so that the rotary movement of the gear is imparted to the piston or hammer rod, while at the same time the latter is free to reciprocate within the frame.

27 indicates a screw threaded shaft which may be carried by any suitable and well known type of stand or tripod. 2S indicates a nut fitted to said screw threaded shaft and carrying at one end the 2S which meshes with and is actuated by the gear 26. his nut has a cylindrical part 26a mounted in a bearing 29 carried by the frame. At its forward end the nut is externally screw threaded as indicated at 28D. 3() and 30 are nuts fitted 'to the screw threaded end 28h and adapted to limit the longitudinal play of the nut within the bearing 29 while permitting its rotation therein.

In operation, power is applied to rotate tue driving shaft 4 in any well known manner as heretofore set forth. Assuming that the toggle joints or links are in their uppermost position as shown in full lines in Fig. 2, the hammer piston then being at the end of its forward stroke the rotation of the crank pin 7 will cause the connecting rod 23 to force the toggle levers 20 rearward bringing their link engaging walls 2()b into positive engagement with the upper edges of the toggle links or oints 18, 19. 'ihe continued rotary movement of the toggle levers about their axes will tend to straighten out the toggle joints, forcing the crosshead rearward vwithin its guide and compressing the spring 13 within the cylinder 1n. The faces 2Oh follow the links 18, 19 to a peint a little beyond the straight position of the toggle joints which are then suddenly released and the links snap across to the extreme position on the under side of the piston rod as indicated in dotted lines in Fig. 2, the spring 13 being simultaneously released and acting upon the shoulder or collar 11L to drive the piston or hammer rod forward to deliver a forcible blow. Prior to the snapping of the toggle j oints to their lowermost position the under link engaging faces 20c of the levers 2() have reached a point somewhat beyond the extreme position of the lower edges of the links 18', 19 so that sudden impact of these surfaces is avoided. i he hammer piston having delivered its blow the reverse movement of the toggle actuating levers is at once started, the link engaging faces 29C coming into contact with their respective toggle links, forcing the joint to straighten out, simultaneously compressing the spring 13 and carrying the joint beyond the straight line position, when its links may snap across to their cxtreme uppermost position and the hammer piston is shot forward as before described. All this time rotary motion is being imparted by the spiral gear 25 to the gear 26 causing the rotation of the hammer piston and consequently the bit or tool, and by the gear 26 tothe gear 2S causing the forward movement of the mechanism as an entirety. rIhe rate of rotation of the drill bit and the rate of forward advance of the mechanism is dependent upon the ratio of the gears and this ratio may be whatever is deemed advisable under the varying conditions to which the mechanism is subjected.

It will be noted that owing to the increasing power' of the toggle joint, as the spring is compressed, great uniformity of work required to be done upon the spring during its compression is obtained, and that I have thus avoided uneven strains upon the power transmitting devices; and this being the fact, a heavier spring may be employed, thereby giving a more forcible blow, than in ordinary mechanisms in which the spring compressing elements are subjected to uneven strains.

I am aware of the fact that numerous mechanisms have been devised for setting springs and then releasing them, themost common of which for drill springs having been actuated by various sorts of cams, but wherever cams have been used great sliding friction has been encountered which causes rapid wear and tear of the parts of the mechanism.

It will be observed that by employing togglc joints as herein illustrated I have succeeded in obviating the sliding friction incident in all drilling mechanisms in which cams are used for setting the springs. It will be noted furthermore that the hammer piston will deliver two blows for each revolution of the crank shaft.

Vilhile in the drawings I have shown a spring which is adapted to be compressed and then released to drive forward the hammer rod, it will be understood that other means may be employed for this purpose without departing from the spirit of my invention.

What I claim is:

1. In a reciprocating drill, the combination of a rod that carries the tool, a frame or casing in which the rod is mounted formed with a guide, a cross-head on the rod and movable in the said guide of the frame, a spring arranged to actuate the rod in one direction, a toggle-joint having one of its links connected with the 'said cross-head and the other mounted to swing about a fixed pivot or axis, and means for straightening out the joint to compress the spring and for permitting the flexing of the joint after the compression has been eected, whereby the spring may act to drive the rod forcibly forward, substantially as set forth.

2. In a reciprocating drill, the combination of a rod that carries the tool, a frame or casing in which the rod is mounted provided with a guide, a spring for actuating the rod in one direction, a cross-head arranged to move in the said guide oI the frame, through which the rod passes, an abutment secured to the rod against which the cross-head is held, a toggle -joint having. one of its links connected with the said cross-head and the other mounted to swing about a fixed pivot or axis, and means for straightening out the joint to compress the spring and for permitting the fiexing of the joint after the compression has been effected, whereby the spring acts to move the piston forcibly forward, substantially as set forth.

3. In a reciprocating drill, the combination of a rod that carries the tool, a frame in which the rod is mounted, a spring for actuating the rod in one direction, a toggle-mechanism for moving the rod interposed between it and the frame in which it is supported, means for straightening out the joint to compress the spring and for permitting the fiexing of the joint after the said compression has been effected, and a rotary riven part connected with and operating the last said means, substantially as set forth forth.

4. In a reciprocating drill, the combination'of a rod for carrying the tool, a frame in which the rod is mounted, a spring for actuating the rod in one direction, a cross -head mounted upon the rod, apair of toggle-joints, said pairs being arranged upon opposite sides of the rod and one link or each pair connected with the said cross-head and the other link of each pair mounted upon a fixed pivot or casing, and means arranged to straddle the said rod and connected with both of the togggle joints, for simultaneously straightening out the said toggle-joints to compress the spring and for permitting the flexing thereof after the compression` has been effected, substantially as set forth.

5. In a reciprocating drill, the combination of a rod for carrying the tool, a frame in whichV the rod is mounted, a s ring for actuating the rod to `deliver its low, a togglejoint having one of its links connected With the rod and its other link pivotally supported on a fixed pivot or axis, a lever 20 recessed on one of its sides to form the Walls or faces 20b and 20C, the link of the toggle mounted on a fixed pivot resting in the said recess, and means for actuating the lever 20, substantially as set forth.

6. In a reciprocating drill, the combination with a blow delivering rod and a spring to actuate it in one direction, of a toggle joint having the outer end of one link connected with the said rod and the outer end. of the other link pivotally mounted on a fixed axis, a lever for engaging said toggle joint and straightening it out, a rotating crankshaft a rod connecting said crank shaft and said lever, and means for actuating said crank shaft.

7. In a reciprocating drill, the combination of a frame or casing formed With a forward cylindrical part la, a central expanded part 1b, and a rear guiding part 1d, a rod for carrying the tool, a spring surrounding the rod and actuating it in one direction mounted in the cylindrical part lEL of the frame, a cross-head through which the rod passes mounted in the guiding part lb of the frame,

and a toggle-joint actuating mechanism for l0 the rod mounted in the part Ilb of the frame, substantially as set forth.

In testimony whereof I affix my signature, in presence of two Witnesses.

GEORGE E. LYNCH. Witnesses H. S. RANSOM, FRANK H. CHURCH. 

